MANCHESTER, United Kingdom, Feb 26, 2026 (BSS/AFP) - Polls opened Thursday in a crunch vote for Britain's ruling Labour party that is expected to highlight growing support for the hard-right and leftists particularly in England, where the traditional two-party system is fracturing.

Defeat for the government in the parliamentary by-election would add to the woes facing unpopular Prime Minister Keir Starmer who endures frequent mutterings about how long he can stay in office.

Labour has dominated the Manchester suburb of Gorton and Denton for decades and won almost 51 percent of the vote there at the July 2024 general election that swept Starmer to power.

Less than two years later, it is locked in a three-way fight for the seat with anti-immigration Reform UK led by Nigel Farage, and the Greens led by leftwinger Zack Polanski.

The battle suggests British people appear increasingly willing to look towards insurgent parties to tackle long-standing, hot-button issues like the high cost of living and irregular immigration at the next general election, expected in 2029.

"It illustrates how the two main parties are losing so much support at the minute," University of Manchester politics lecturer Louise Thompson told AFP, referring to Labour and the main opposition Conservatives.

"It could be a real sign that they are in a lot of danger."

Starmer, whose five predecessors as prime minister were all Conservatives stretching back to 2010, has pitched the by-election as "a battle of values".

He told parliament on Wednesday that Reform offered only "grievance and division" and accused its candidate of saying that "anyone who isn't white cannot be English".

Starmer also attacked the Greens' support for legalising drugs, calling it "reprehensible".

- Epstein row -

Polanski responded to similar comments from Starmer earlier in the week by calling Labour "vile".

The vote was triggered by the resignation of former Labour MP Andrew Gwynne on health grounds.

Matt Goodwin, a 44-year-old political scientist, is bidding to become Reform's ninth MP in the UK's 650-seat parliament.

Standing for the Greens is Hannah Spencer, a 34-year-old plumber and trainee plasterer, who is hoping her party's pro-Palestinian stance will appeal to the constituency's 28 percent Muslim population.

Local councillor Angeliki Stogia was chosen as Labour's candidate after the party's ruling body blocked the candidacy of Manchester mayor Andy Burnham, popular among left-wing activists.

Burnham's bid to try to become an MP was widely seen as a precursor for a potential leadership challenge against Starmer, from the party's centre-right.

Starmer faced down calls to resign earlier this month amid a row over his appointment of an associate of sex offender Jeffrey Epstein as Britain's ambassador to Washington.

The envoy, Peter Mandelson, was arrested Monday on suspicion of committing misconduct in public office over allegations he leaked sensitive financial information to Epstein as a minister over a decade ago.

Starmer has also taken flak for countless policy reversals and polls suggest he is the most unpopular British prime minister since surveys began.

A win would help quieten the noise around his future before he faces a bigger moment of peril in May with elections in Scotland, Wales and London that pollsters predict will be painful for Labour.